Furnace with rotary grate



E. BOMANET. FURNACE WITH ROTARY GRATE.

1,371,056. APPLICATION FILED JUNE 6' I918. Patented Mar. 8,

9 SHEETSSHEET l- ATTOlP/YIK Rama's PETERi lhC Lwc. WAshme-wx B C E. ROMANET. FURNACE WITH ROTARY GRATE. APPLICATION FILED JUN6. 191s.

Patented Mar. 8, 1921.

L 8 SHEETSHEET 2- T l fmi/e Rama/16f 4 TTQANEYS I non'aslPzrans m LHHmM/Ammmcn o c E. ROMANET.

FURNACE WITH ROTARY GRATE.

L Q3 1T 4 Mn Mn M Ma H m P 8 m Aw E N m D H N 0 H A c U P DI A Nouns PETERS. Inc .Lmio WASHrNGKml u c E. ROMANET.

FURNACE WITH ROTARY GRATE.

APPLICATION FILED JUNE 6. I918. 1,371,056. Patented Mar. 8, 1921 8 SHEETS-SHEET 4.

ATTORN Y NORRIS PETERS. INC. LITHO WASHINGTON D C E. ROMANET.

FURNACE WITH ROTARY GRATE.

APPLICATION EILED JUNE 6, 1918. Mar. 8

8 SHEETSSHEET 5- AI'FUR/YEYS NORRIS PETERS. INC Llmcu WASHINGIUN D C E. ROMANET. FURNACE 'WITH ROTARY GRATE.

APPLICATION FILED JUNE 6., I9I8- Patented Mar. 8-

8 SHEETS-SHEET 6- ATTORNEYS E. ROMANET.

FURNACE WITH ROTARY GRATE.

APPLICATION FILED JUNE 6, I948.

Patented Mar. 8, 1 92]v 8 SHEETS SHEET 7.

1 will mans/wax? 577/49 Kama/re) E. ROMANET.

FURNACE WITH ROTARY GRATE.

, APPLICATION FILED JUNE 5,1918. 1,371,056 Patented Mar. 8, 1921.

8 SHEETS-SHEET 8.

//VVE/Vr0/? A ni/e Rama/767" NuRms PETERS, 1N0, Limo wnsnmmcm D C UNITED STATES PATENT OFFICE.

FURNACE WITH ROTARY GRATE.

Application filed June 6, 1918.

To all whom it may concern:

Be it known that I, EMILE ROMANET, a citizen of the Republic of France, residing at 17 Rue de lElyse, Grenoble, lsere, in the Republic of France, have invented new and useful Improvements in Furnaces with R- tary Grates, of which the following 1S1}, specification.

This invention relates to boiler and other furnaces having rotary grates, the object being to provide a furnace of this kind the upkeep and attendance of which are easy while deterioration through clinkers is avoided, and regularity of draft through all parts of the grate is insured, as well as perfect combustion over the entire surface of the grate covered by the fuel.

Several ways of constructing a furnace according to the invention and its constituent 20 parts are illustrated in the accompanying drawings by way of example.

Figure 1 is a vertical section of a furnace on the line 11 Fig. 3.

Fig. 2 is a front elevation of the same.

Fig. 3 is a horizontal section on the crooked line 3-3 Fig. 1.

Figs. 1 and 5 are respectively a plan and a transverse section of one of the grate elements.

Fig. 6 is a horizontal section of the central fixed trunk or body, on line 6-6 of Fig. 1.

Figs. 7 and 8 are respectively an elevation and a plan of one of the sliding plates or doors bounding the, combustion chamber with its controlllng members.

Figs. 9, 10 and 11 are respectively a partially longitudinal section, a transverse section and a plan of an actuating device for rotating the grate.

Fig. 12 is a transverse section of a device for raking the fuel, taken on the line C, C

Fig. 1.

Fig. 13 is a vertical section of a similar furnace provided with a small auxiliary furnace for the purpose of igniting the fuel.

Fig. 14 is a horizontal section on the line D, D Fig. 18.

The construction represented in Figs. 1 to 12 comprises a central fixed and hollow trunk or body 1 around which can revolve the annular shaped grate a. Beneath this grate a chamber 4 is provided open for the greater part of its periphery from the ground to the level of the grate.

The periphery of the grate rests upon a Specification of Letters Patent.

Patented Mar. '8, 1921.

Serial No. 238,556.

series of rollers 5 carried by uprights 6; it is provided with a toothed ring? with which gears a pinion 8 to which is imparted an intermittent rotary motion from a suitable source of motive power through the medium of a driving mechanism hereinafter which can run upon a circular rail 18, thus sustaining the door in its closed position.

'At a point in its circumference the rail 18 is mutilated and thereby permits the door to open by its own weight to allow the ash and cinders to fall which have been received in the compartment 12 during the preceding revolution of the grate.

Above the grate are placed the radially disposed bars 19. Each bar is preferably of trapezoidal shape as shown at Fig. 1; it consists of longitudinal portions 19 placed at a small angle to one another and joined at their ends and also, if required at one or more intermediate points by transverse parts 19 each longitudinal member is provided on both of its lateral faces with'projections 19 increasing in length from the center toward the periphery of the grate; so that the complete bar has the form of a ring-segment.

Around the grate is arranged a metal ring 50 resting upon the uprights 6 and supporting a brick wall 20 of the grate; the ring'50 is divided into several parts in order that it shall not get out of shape through the eX- panding action. The Wall 20 of the grate has at 20 a bridge and, at the opposite side of the latter, openings 21, 22, 23 provided with doors 21, 22 23. Between the said openings and the bridge is placed a front wall of brickwork 24: supported above the grate and the central trunk or body 1 by a reinforcing plate 25, a space being left be tween the under side of the said wall and the top of the grate.

The combustion chamber occupies only a part of the circular s ace above the grate; it is bounded at the side of the front by two partitions formed by sliding plates or doors 26 and 27 arranged radially between the openings 21, 22, 23 and movable in guides 28, 29.

In the space between the plates 26, 27 outside the wall 24 is placed a coal hopper 31 the bottom of which opens over the grate against the plate 26 and can be more or less obstructed by the latter.

The plate 27 is designed to close the combustion chamber on the side where the fuel issues and, also, to keep back the coal not yet consumed at the surface of the bed of fuel, the height of this plate being regulated so as to allow, as far as possible, only slag and clinker to pass over the grate.

Between the hopper 31 and the plate 27 is placed a scraping device 32 which extends in a slightly oblique direction with relation to the radii of the grate above the latter and above the sill of the opening 22. This device is adapted to clear the grate from the residues of combustion passed beneath the plate 27 and to bring them into a discharge aperture 33 provided in the sill of the opening 22; these residues fall into a receptacle 34 placed beneath the aperture 33.

The air required for combustion is conducted from a blower (not shown) into the compartments 12 through several channels 35, 35", 35 35 placed in the ground, and opening under the trunk or body 1, the said air then rising through conduits 36*, 36 36, 36 formed by partitions 3 3 3, 3, in the interior of the trunk or body, then through openings 37 37, 37, 37 provided in the periphery of the trunk or body, and openings 38, in the inner ring 9 of the grate. The openings 37 to 37 are so placed as to feed air only to the compartments 12 situated beneath the combustion chamber, so that the compartments corresponding to the intervening space (front side) between the sliding plates or doors do not receive the forced draft. The circular rail 18 is mutilated just beneath this intervening space so that the compartments open downward and allow their clinkers to fall at the moment when they are not receiving air.

The different channels 35, 35*, 35, 35 are provided with sliding dampers 39, 39 39, 39 respectively which allow of regulating the supply of air through the sections of the grate corresponding to the openings 37 37*, 37, 37 This arrangement allows of accelerating or slackening the combustion at the points where it is thought advisable.

In order to prevent any downward escape of air between the trunk or body and the grate, a sand joint is provided as follows: the trunk or body 1 carries at its periphery an annular trough 46 containing fine sand 41 into which dips a rib 42 extending down- 45 indicates an arrangement of piping,

for water under pressure supplied from a suitable source, carrying short tubes 46 which pass tight through the wall of the trunk or body 1 and have their ends inclined upward and outward, each of the said tubes terminating in a sprinkling nozzle 47. Each time one of the covers 39 of the grate passes in front of the nozzles 47 the jet of water spouting out upward sprinkles the bars 19 and cools them. 7

Each of the plates 26, 27 can be raised and lowered (Figs. 7 and 8) by means of controlling mechanism comprising for example a vertical rod 48 fixed to the plate and having a screw-threaded part 48" on which turns a nut 49 which is held vertically in position by a support 51 and which is provided with a toothed ring52 with which gears a screw 53 fixed on a horizontal shaft 54 designed to be turned by means of a hand wheel 55.

The mechanism for actuating the grate is represented at Figs. 9 to 11. It is designed for the purpose of obtaining a very great ratio between the speed of the driving shaft 56 of the works and the speed of the grate, and for allowing the. variation of this ratio within very wide limits and in a continuous manner.

This mechanism comprises a drum 61 having a flat rim or plate on the inner side of which the ends or feet 62 of two levers b come jammed. These levers are movable upon pivots 63; they carry at one of their ends the feet 62 and, at their other ends joints connected to the control-lever 64 through the medium of toggles 6 5 and a sleeve 66 having legs and movable around the shaft 67 Owing to the unsymmetrical form of this plate it constitutes a counterweight'which always tends to turn around the shaft 67 in the opposite direction to the arrow. I

The lever 64 has a rocking motion given to it upon the shaft 67. When the motion is in the direction of the arrow the jointed ends of the levers 62 are also displaced in the direction of the arrow by the toggles 65. The pivots 63 being moved in the reverse direction, since they are fixed to the plate 68, the feet become jammed onto the rim of the drum and carry it along in their movement without any possibility of slipping.

When the movement of the lever 64: is reversed the jointed ends of the levers 62 are displaced in the opposite direction to the arrow and release the feet; but the counterweight-plate carrying the pivots '63 along in the same direction, the feet remain in contact with the rim of the drum by the simple pressure due to the counterweight of the plate; this pressure may be as weak as desired and such that the feet do not carry the plate backward. The continuity of contact thus obtained prevents any loss of motion at each movement of the drum.

The lever 64 is jointed to a sleeve 69 placed free upon the screw-threaded end of an eccentric rod 7 O. This rod carries a fixed nut 71 and a movable hand wheel nut 72 the displacement of which modifies the stroke utilized by the lever'64. This stroke can therefore vary from the full stroke of the eccentric to zero, using any of the intermediate valves'. The advance of the feet 62, and consequently the angular speed of the drum 61, will vary in the same proportions. The interposition of springs or spring washers 73 reduces the shocks of the nuts 71 and 72 on the sleeve 69.

A safety device for preventing breakage, consisting of a bolt 7 1 of a given section, connecting the boss of the lever 64: to the sleeve 66, obviates rupture of any part, whether of the mechanism that it is intended to actuate, or of the change-speed apparatus.

The intermittent rotary motion of the drum 61 is transmitted to the grate through the medium of the pinion 61 fixed to the drum and of a wheel 8 keyed on the shaft of the pinion 8.

The raking device 32 (Figs. 1, 3 and 12) consists of an endless chain 32 passing around chain wheels 75, 76, carrying a series of rakes 32 and brushes 32 movably secured to the chain-links.

The wheel 75 is fixed on a shaft in two parts 77, 77 carrying a pinion 78 placed beneath the ring 50; this pinion gears with a wheel 78 fixed to a bevel pinion 79 and the latter gears with another bevel pinion 79 fixed on a shaft 80 which carries another pinion 81 gearing with the toothed ring 7. During the rotation of the grate, the rotary motion is transmitted by the above described gear to the wheel 7 5 which carries along the chain 32*. The shaft 77 is held at top and bottom by bearings or supports 82, 83, which are connected to the ring 50. On the other hand, the wheel 76 turns freely upon a shaft 8& fixed in a support 85 which slides in a guide 86 fixed to the support 83, and this sliding support is united to the end of a horizontal rod 86 the opposite end of which is screw-threaded and screws in the support 83. By screwing this rod the required tension can be put upon the chain. By slackening the two bolts 83 which secure the support 83 upon the ring 50, the raking device can be removed in one operation wh1le only leaving in position its control-mechanism situated beneath the ring 50. To this end the shaft portions 77 77" are united by a key 77 and a ring 77 so that they can easily be separated from each other; moreover, the inner end of the guide 86 is simply inserted between two projections 25 on the plate 25 and are thus conveniently supported above the grate.

The furnace with rotary grate thus constructed combines numerous advantages; the grate is Well equilibrated and can turn freely on the rollers 5 and 43. All the mechanism whereby it is actuated is entirely visible and easily accessible. The admission of the air at the different points of the grate can be regulated as desired as well as the speed of rotation, which allows of using any kind of fuel to the best advantage. The said joints insure tightness and prevent the escape of air and dust outside the furnace. The plates of the furnace, the bars and other parts of the grate can freely expand. They are, besides, kept at a moderate temperature by the water sprinkling arrangement. The slag received in the rotary compartments 12 is automatically discharged at a given point of the rotation. It is the same with regard to the cinders and clinkers which are eliminated b the raking device 32 so that the grate a ways remains in proper condition for the air to pass through it.

In the modification illustrated in Figs. 13 and 14 the furnace only differs essentially from that illustrated with reference to Figs. 1 to 12 by theaddition of a small auxiliary furnace E which serves to insure the ignition of certain kinds of fuel which are very poor in combustible materials.

This small furnace comprises, for example, a fixed grate 87 on which can burn wood or coal having a long flame. It is so placed that the heat given off from the fuel on the grate 87 is deflected by the arch 88 on to the coal which passes beneath the sliding plate or door 26. This heat first causes a distillation to begin and then the ignition of the distilled gases and carbon.

89 indicates the charging door of the furnace E and 90 the ash pit door.

Instead of a coal furnace E an oil or gas furnace can be employed.

In grates constructed according to the herein described invention the combustion surface is horizontal; but the bars can be so arranged that the combustion surface is conical, the periphery being higher or lower than the center.

I claim:

1. In a rotary-grate furnace, the combination of an annular grate composed of a series of sections, each section having a kind of hopper, grate bars over top of the said hopper and a discharge trap at the bottom of the hopper, and means for controlling the opening and closing of the said traps during the course of each revolution of the grate.

2. In a rotary-grate furnace the combination of central fixed trunk or body having air passages within it opening at the top at its periphery, an annular grate revolving around the said trunk or body, the said grate comprising an annular trough, radial partitions forming compartments in the said trough and bars covering the said compart ments, the inner Wall of the said grate being adjusted to turn around the trunk or body and having apertures adapted to pass in front of upper openings in the said passages in the trunk or body.

3. In a rotary-grate furnace thecombination of a central fixed trunk or body having air passages Within it opening at the top at its periphery, annular grate revolving around the said trunk or body, the said grate comprising an annular trough, radial partitions forming compartments in the said trough and bars covering the said compartments, the inner Wall of the said grate being adjusted to turn around the trunk or body and having apertures adapted to pass in front of upper openings in the said pasplate, the said levers having at their outerends feet adapted to bear against the inner periphery of the said drum, the inner ends of the said levers being connected to the said lever, and means for imparting to the said lever an adjustable to-and-fro motion, the said plate being unsymmetrical so that its Weight tends to keep it or to return it to a given position of rest. 7

5. In a rotary-grate furnace, a raking device comprising a horizontal guide, a fixed bearing at one end of the said guide, a bear ing movable along the said guide, vertical shafts in the said bearings, chain Wheels upon the said shafts, a chain passing around the said Wheels, raking members upon the said chain and means for regulating the position of the said movable bearing upon the said guide.

EMILE ROMANET. 

